1010] HaUejfR Cnynpf. 75:5 



WEEKLY EVENING MEETING, 



Friday, February 18, 1010. 



Sir Francis Laking, Bart. G.C.V.O. M.D. LL.D., 

 Vice-President, in the chair. 



Herbert Hall Turner, Esq. D.Sc. D.C.L. F.R.S., Savilian 

 Professor of Astronomy in the University of Oxfoi'd. 



Halley's Comet, 



The published records of the Royal Institution mention no lecture 

 on comets previous to 1<S82. In 1885, Avhen Halley's comet was 

 last with us, the publication of the records was suspended : but with 

 the kind help of the Assistant Secretary, Mr. Young, references were 

 found in the " Records of General Science " to two lectures given 

 liere on April 10 and May 1, on Halley's comet, by Dr. Lardner. 



He gave an account of the calculations which had been made by 

 Lalande and Clairaut, with the help of Madame Lepaute, for the 

 return of 1750 which Halley had predicted ; mentioning how these 

 three earnest workers had toiled incessantly day and night, not 

 excepting meal times, for six montlis : how they were handicapped 

 by their ignorance of the existence of the planet " Herschel," of 

 which the mass. Dr. Lardner remarked, was still an uncertain 

 cpiantity (and Neptune was of course then unsuspected) ; how 

 Voltaire had said that astronomers never went to bed in 1758 for 

 fear of missing the comet ; and how it was at last discovered on 

 Christmas day by a farmer near Dresden. He estimated that there 

 were 7 miUion comets in our system, and considered that the mass of 

 a comet could not be as great as one five-thousandth part of that of 

 our earth. Some of the phraseology reads a little strangely to us 

 nowadays. " All the planets," he said, " are collected in the Zodiac, 

 from what cause we are not aware." Comets, on the other hand, are 

 not so collected, and the ellipticity of their orbits " does not depend 

 upon physical laws, but upon the will of the Creator." 



The publication of the Proceedings of this Institution was re- 

 sumed in 1851, but the first nine volumes contain no reference to 

 comets in the index,* although the period to which they refer includes 

 the conspicuous comets of Donati in 1858 and TeJjbutt in 1861. 



* Since these words were in type, Mr. Young found that Professor Robert 

 Grant delivered a course of seven lectures at the Royal Institution in 1870 on 

 "the Astronomy of Comets," and that a report appeared in the " Illustrated 

 London News " of that year. 



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